Copying machines in which sets of originals are automatically recirculated and which are suitable for processing both simplex originals and duplex originals, i.e. originals provided with information on one or both sides respectively, to form simplex or duplex copies, are required to satisfy an extensive range of requirements by users. This range or requirements includes: simplest possible procedure for all combinations for processing simplex or duplex originals to form simplex or duplex copies; a readily visible and clear operating situation; a compact construction; good accessibility to the feed, turnover and discharge paths and also to the cassettes; and of course optimal productivity of the machine.
With regard to the operating situation aspect, this must be optimal in order to avoid any confusion on the part of the operator, e.g. during clearing and repairing a fault in the transport of the originals. A good aid in such a situation would be that the sequence of the originals in the cassettes during the processing of the copying order should always agree with the original sequence of the set of originals. With regard to productivity, it is desirable, particularly for high-speed copying machines, that it should be possible to insert in readiness at least one subsequent set of originals for the most usual copying orders, which are still the processing of simplex originals.
An apparatus for supplying and discharging originals in a copying machine is disclosed in DE 36 31 129 Al. Although this known apparatus satisfies a number of the above requirements, it does so at the expense of complex circulation through feed, turnover and return paths for the originals, even for the simplest processing of simplex originals to simplex copies.
GB-1,544,045 discloses a similar apparatus in which, although it uses less complex original flow paths, the sequence and orientation of the originals in the set in the case of duplex originals is changed between the first and second cassettes. The operator is thus faced with a confusing situation when clearing a malfunction in the original flow. Depending upon which cassette is to be used for deposition of the duplex originals, a specific sequence and a specific orientation (with the first image side up or down) must be selected. To enable simplex originals to be processed to form copy sets with a logical sequence of the copy sheets, they must be placed in the second cassette in the logical sequence, with page 1 at the top, or be placed in the first cassette but, in that case, so that the image-bearing sides are face down and the first sheet is at the top.
U.S. Pat. No. 4,231,561 describes an automatic document feeder for use in a duplex copying machine. This feeder is not suited for handling simplex originals and has several of the disadvantages mentioned above. U.S. Pat. No. 4,814,822 discloses a copier used for producing booklet form copysets. As such, it is designed to present the original sheets in the required "two-up" mode and is not well suited for handling a wide variety of originals. All in all, this is an operating situation which readily results in mistakes and hence incorrect processing of the copying order.
It would be desirable therefore to provide an apparatus for supplying and discharging originals in a copying machine wherein the originals are always in the original sequence in the cassettes, and the simplest possible flow path is achieved for the processing of each original type, while in addition the next set of simplex originals can be placed in readiness while one set of simplex originals is actually being processed.